Plates, beams, posts, rollers, pusher plates and muffle liners for industrial sintering and heat treating.
In a pusher furnace the furniture travels with the product, cycle after cycle.
Its grade decides how many trips it makes.
In continuous furnaces, silicon carbide kiln furniture usually lasts longest where the atmosphere is oxidizing or neutral and the load is high: recrystallized and nitride bonded silicon carbide keep their strength and resist creep at temperature, so plates and beams stay flat in thin sections. In hot hydrogen or other reducing atmospheres, low silica, ultra high alumina often outlasts silicon carbide grades that rely on a silica rich bond. Blasch casts pusher plates, plates, beams, posts, rollers and muffle liners in both families, engineered for one furnace and one product.
Pusher plates: each plate is pushed against the one in front for the whole length of the furnace. Edges chip, the sliding face wears, and every entry into the hot zone is a thermal shock.
Plates and beams: under constant load at temperature, a weak grade creeps and sags until the stack tilts.
Posts and rollers: small cross sections carry the whole load and must stay straight, or the ware moves out of position.
Muffle liners: the muffle separates the process atmosphere from the heating side. A crack lets atmosphere through and changes the result on the product.
In a continuous furnace the plate that costs the least is the one you do not have to change, because every replacement means sorting, cooling or slowing the whole line.
The word silicon carbide covers several materials with different bonds. For kiln furniture the bond matters more than the carbide content.
| Grade | Strength at temperature | Suited to |
|---|---|---|
| Recrystallized SiC | high, no secondary bond phase | thin plates and beams in oxidizing kilns |
| Nitride bonded SiC | high, nitride bond | plates, beams, posts under load, good oxidation resistance |
| Reaction bonded SiC | dense, contains free silicon | beams, rollers and wear faces below the limit of the free silicon |
| Ultra high alumina | lower than SiC, very little silica | reducing and hydrogen atmospheres |
| Mullite, cordierite | moderate | supports in fast thermal cycling |
Blasch casts these grades near net shape, so slots, locating features and pusher edges are formed in the mold rather than ground in later. Nitride bonded silicon carbide
Muffle liners and burner parts in the same furnace see the hottest and most uneven temperatures. They are cast as one piece where brick would leave joints, with walls thinned where heat must pass and thickened where they carry the load.
Replacing thick cast blocks and plates with an engineered low mass assembly lowers the dead load on each pusher plate or car. The furnace then heats more product and less refractory, and heat up and cool down get shorter.
Furniture that carries the load is one part of the furnace, the parts that hold the product and the heating elements are the others.
Containers and setters for calcining battery powders and sintering MIM and powder metal parts.
Ceramic holders and insulators that keep electric heating elements in place at temperature.
Burner parts, supports and shapes for furnaces in heat treating and firing.
It depends on atmosphere and temperature. Nitride bonded and recrystallized silicon carbide suit oxidizing service, low silica alumina suits hot hydrogen atmospheres.
The cold plate meets the hot zone and the faces heat faster than the core. A thinner section and a grade with higher thermal shock resistance reduce that stress.
Yes. The dimensions of the current plate and the push direction are enough to design the replacement, with locating features cast in.
Yes. Blasch engineers can design the whole support structure around your ware, from plates and posts to beams.
Send the furnace type, atmosphere, peak temperature and the dimensions of the current plate. A Blasch engineer proposes a grade and a design.
